You can set up content rules to automatically
perform an action when certain events (known as "triggers") take
place. For example, you can set up a content rule to send an email (the action)
whenever certain (or any) content is added to a specific folder (the trigger).
Some other examples of what content rules can do are

• Move content from
one folder to another when that content item is published

• Send email when a
content item is deleted

• Delete content
after a certain date

As
an example, for one Falcon site the admins get an email when any member edits
their profile in the research directory.

For
a full tutorial see http://plone.org/documentation/kb/using-content-rules/tutorial-all-pages